The present invention provides the universal equipment for cooling fluid regeneration via heat exchange circuits.
The invention applies water cooling heat exchange circuits to industrial machines such as ice cream production machines or plastic material moulding machines (moulds cooling), etc.
It is known in the art that there are many types of machines using water cooling circuits which generally discharge the waste water without recirculation. Recirculation involves high costs and consumption of water which nowadays is so precious.
The cooling water generally exits at a temperature about 35-40xc2x0 C.
To avoid the high costs deriving from waste of the cooling water, equipment recirculating the water by cooling it were studied.
This equipment is substantially made like a cooling tower which involves the recirculation of the water from the to-be-cooled machine, and is subject to a heat exchange by passing through a forced air-jet and by using an evaporating system, which eventually and preferably are combined with the heat exchange along with frigorific circuit condensing panels.
In the cooling tower and in the water-air exchanger (evaporating type), the temperature at which the water may be regenerated cannot go below the temperature of the humid bulb of the air used.
A water-air exchanger of the non-evaporating type (for example, dry-finned exchangers), the temperature at which the water may be regenerated cannot go below the temperature of the dry bulb of the air used and thus the range for temperature decrease is even more limited.
Also auxiliary cooling machines which use condensers operating in closed cycle frigorific circuits have the drawback of being unsuitable for different periods of the year or different specific needs.
It should also be considered that if the cooling apparatus does not always cool the machine with water in proportion, a vicious circle may actually endanger the machine and may even cause other damage.
Obviously these problems may be reduced if the machine is cooled by using the disposable system water, because in this case the system water during the day has substantially the same temperature. Therefore, it would only be necessary to vary the water delivery for running the machine to be cooled perfectly, but this solution would be extremely expensive and ineffective in summertime. Therefore, it is certainly more convenient using the equipment of this invention to substantially realize a closed cooling circuit.
In the case of a closed cooling circuit, if the cooling apparatus does not eliminate all the temperature increases, which the working machine yields, the closed circuit water temperature, tends to continuously increase in a vicious cycle which is difficult to eliminate without damaging the operating machine.
If, for example, the increase of the water temperature, which circulates in the operating machine, is 15xc2x0 C., it is obvious that the cooling apparatus should subtract exactly 15xc2x0 C. If it subtracts only 14xc2x0 C., at each water recirculation, the water will increase its temperature just a little less than one degree and even if progressively less, thereby reaches a point that endangers the work and damages the machine (operating) due to inadequate cooling of the operating machine circuit.
Vice versa, if the cooling apparatus subtracts too much temperature, the working machine would work in non-optimal temperature conditions.
DE 296 06 863 U1 (BKZ ANLAGENBAU GMBH) discloses a device for cooling liquids with a freezing coolant closed circuit.
FR 2 544 470 A (HIROSS INTERNATIONAL CORP. S.A.) discloses a cooling unit for cooling fluids in an air conditioned installation with vent supply.
The object of the present invention is to obviate the above-mentioned drawbacks by creating equipment for supplying cooling water which is proportional to the working machine""s needs, independently of the same machine working charge and of the environmental temperature, and also to be able to adapt to any cooling condition, both by cooling tower means and frigorific means, jointly or independently.
These and other objects are achieved as claimed by cooling equipment, which may be connected to the water discharge from a to-be-cooled machine and makes the water recirculate once cooled. The cooling equipment includes:
at least one cooling tower with an extended surface to be wetted by the water so that a portion of the water was evaporated;
at least one air draft generator device for forcing air through said cooling tower so as to cool the water and thereby minimize the water form evaporation;
at least one closed cycle frigorific circuit:
whose condensing means, such as condensers, are placed downstream of said cooling tower placing with respect to said air flow; and
whose evaporator is placed downstream of said water circuit for exchanging heat with the water cooled in said cooling tower for subsequent recirculation in said operating machine.
said condensing means being two, one placed upstream and opne downstream of said cooling tower and at least on of the condensing means being activated.
Thus, the invention makes the cooling system more effective and with a higher yield, and reduces the temperature of the water to be cooled to a rather low value (reduced heat exchange thermal head).
In the preferred solution, said condensing means are placed both upstream and downstream of said tower, which makes possible a maximum cooling by operating in both conditions.
It is more advantageous when the following additional means are provided:
water temperature sensing means (Te), such as a sensor at the entry port of the hot water, and controlled valve means for discharging the hot water on the entry port in certain conditions;
between said hot water entry port and the cold water exit port, means for letting in cold water from a supplying system;
on the cooled water exit port, cooled water temperature sensing means;
means for comparing one and/or the other temperature and at least one exit port for operating said valve means (for the hot water discharge and cold water inlet on entry).
Another advantage is to perfectly calibrate the cooling plant with less water loss.
It is advantageous that the panel in contact with the cooling tower is extractable which makes possible a further cooling under certain conditions by operating only the frigorific circuit.